Several systems for wireless transmission of (sensor) data by means of RFID technology have been known. For example, transponder ICs (integrated circuits) exist which may capture analog data of an external sensor. Said sensor data may be read out via RFID standard protocols while using an RFID reader. Partly, this involves an external voltage source (e.g. battery) if the system is to fetch the sensor data at specified times. If no external voltage source is used, the sensor data can only be established and/or read out at those times when an RFID reader is within reach to supply the system with energy. Some available systems exhibit predefined integrated sensors (e.g. only temperature). Also, in many systems, the number of the sensors to be connected is limited (e.g. three at the most). In addition, in most systems only such sensors can be employed which feed back analog measurement values. Said analog values are then converted to digital data within the system (transponder system).
Thus, utilization of external voltage supplies such as batteries is often the case in known systems. In addition, there is a limited number of sensor inputs of the system, e.g. a restriction to one sensor. Connection of external sensors is limited to a specific type of connection, e.g. to purely analog sensor input signals or only SPI (serial peripheral interface). Also, sensor data can only be determined at those times at which an RFID reader is present, since said reader makes an alternating magnetic field available to the system as an energy source. Moreover, existing systems are mostly specified to only one sensor type (e.g. temperature).